Swivel pipe joint



y 1949. E. REZLER 2,477,142

SWIVEL PIPE JOINT Filed May 14,- 1946 l Fi9.1

42 43 Inventor:

Emit REZLEg i 'atentecl July 26, 1949 :SWW'EL PIPEn-IQINT Emil"BezlerfPrague' Smichov, Ezechdslovakiamssigner to limited Gompan'y, formerly The Skodaworks Plzen, Prague, flzech'oslo vakia, a .1 corp oration of Czechoslovakia .ApplicationMayM,

1946,.JSeii'aiI No. 1669,1245

: ssctionzi; Public Law 16911, nug us tiazaiaie iiPatent :expires August 2,1963

"'3Clainis. (013285-1873) -The-.-admission. of-pressure air into the rotating air 1 cylinder I machine-tools, 1 .e. g. into! the air acylinder of the chucking:device, siseeffected in :diitherto familiar devices by means of a: distribur-itor socket whichlatter is immobile and surrounds ithe .-rotating; pivot-. of the clamping .1 cylinder.

In such arrangements it is. essential to provide aforha perfectpacking of the socket. on the rotatin -pivotisoas' to reduceair losses to -:aminimum. In .those cases-where the Working spindle -whereon stheaaircylinder is fixed turns at smaller speeds -and \more ,lparticularly vin such cases *where the gpivot -is.- of a. small-diameter, .i. -;e. ior-smal=lerrcircumferential speeds, the solution of-theproblem iof assatisfactory packing of said-socket meets no particular difliculties.

The problem of a satisfactory packing of-said ssocket is much more difficult :to solve; in: arrange- .mentszconta'ining aspivot ofai'large idiameter esspecially =.-in -.the :case f modern high-speed t-re- .volver :lathes wherein the :material *wherefrom dahe-respectiveobj cots are. tozbe turned, =is;:passing in rod 1.:s'hape through the hollow spindle. The diameter of the distributing sleeve is thereby excessively increased so that the circumferential .speed at high turning speedsis very considerable. "The pivot of the clamping CYIiHdGIiSaBXCGSSiVElY heated and there occurs the risk of socket seizing owing to the decreased-clearance.

The isubstantial drawbacks of the hitherto tthe .caseszof large .diameters and highlturnitng speeds consist in the intricate design of the packing, in the considerable loss of working energy owing to the excessive friction occurring between the sleeve and the pivot, in the high air losses due to leakage and in the unequal clearance at various turning speeds owing to the uneven heating of both frictioning parts.

The above mentioned drawbacks are eliminated by the arrangement according to the present invention. The chief feature thereof consists therein that the packing is brought about by means of a simple conical surface of such an apex angle that any risk of self-clamping is avoided. The advantage of such tapered contact surface over a cylindrical one consists therein that if by being heated at higher turning speeds the pivot presents a diameter more enlarged than is the diameter of the socket sleeve no risk of seizing occurs in contradistinction with cylindrical surfaces. In the arrangement according to the present invention the socket is axially displaceable so that the clearance between the pivot and the socket is maintained at a minimum and at con- 22 t-stan-i size. Inisuch-ran arrangement vvvhereinethe certain minim-um clearance iis always .smaller (than in Lthe ease --of. a-.cylindrical ,socket and wherein Joy such; small clearance ionly a trifling .5 eamountscfaain escapes, the; rotating, pivot isiglidsing on an air -bolster z-almost without any m-e- :chanical friction. The resulting:axialiiorceypro- :dueed by Fthe sair pressureewith-in the faboveimenrtioned clearance, ,z-is equalizedcby .the pressure .10 e lpon-ithe socket" resulting irom ther same source -.=aswthe -.air 5 pressure ini the clearance ands-coming eiriom -.an auxiliary ecylinder. .iThereby Tia .-:satisi factory %balance :is :attained :between -:the 2* axial .iiorcesweven at substantial fluctuationsmf the air e pressure,sassis frequent in practisegthus ensuri-ng :a sconstant minimum =z-clearance mecessary efor vavoidingwseizingxiofi therpivot :even at iiifierenteair tp'ressures. Y

If no pressure air .is -admitted1through the ssocket sand if ;there :is 1110 ."overpressure the clearancethe-ipressing ion TOflthBES'OCkBt'. onto lthe lfiiVOt :fis aautomatically .interruptsd tbyfimeams 'rof rthe-sauxiliary cylindemso thatpin :thisrcasartm,

.sseizing: isia-voided. tin:suchcasezthexsoeket. isrr'eileasedisothat-frictionlossesiare small.

The :accompaniing drawing. shows, merely cby iway so seXamplec-an: embodiment wf the s' obiect eofsthisednvention. rEig. his:iarlotrgitudmalsection of the distributionsocketsinzconnection-witlrthe '30 airccylinder'aandzFig. 22a *crosszsettionat view on rknown packing arrangements zof the is'leeve tin rth IinaA A mEigzI.

.fieterring mow :to 'sthe ifigures, aarconical ring 3 is pressed upon the pivot l of the air cylinder 2, said conical ring presenting a bearing surface to 3 the socket 4 where through pressure air is introduced from the pipeline 5 into said air cylinder 2. The socket 4 is pressed against said rin 3 by the piston 6 of an auxiliary cylinder I the piston rod 8 of which is connected to an annular disc 9 whose pivots H], H are engaged in openings of said socket 4, said annular disc bearing through a spherical pivot I2 against the recess 13 of the bracket l4 fixed on the head stock whereby any mutual angular displacement of said annular disc 9 and said socket 4 is prevented.

The air for said auxiliary cylinder 1 is introduced from the same piping 5 as the air for the socket 4 so that the air pressure is identical. In case there is no air admitted through said socket 4 the piston is in its left-hand rest position and said socket 4 is slightly urged against the conical ring merely through the action of a spring l5.

Since it is difiicult to predetermine the proper size of said auxiliary cylinder 1, it is preferable to choose a somewhat larger diameter of said cylinder and to keep the force brought about by its piston 6 within certain convenient limits through the action of an adjustable spring l6.

It is well known to spray oil automatically into the air at the entrance of pressure air devices, said oil having the purpose of protecting the respective surfaces and of lubricating said surfaces.

This well known principle has been utilized according to the present invention for automatically lubricating the conical surface during that working period when the air is left out of the air cylinder. Air draining out of the cylinders is carried out through such displacement of the control organ I8 that the piping is connected to the exhaust I9. The arrangement according to the present invention is such that a return valve I1 is provided in that part of the piping which leads to the air cylinder 2, said valve allowing introduction of air into the air cylinder but preventing any escape of the air from the air cylinder 2 through said piping into the exhaust 19. In the case of air draining, therefore, air escapes merely from the auxiliary cylinder 1 into the exhaust I 9 so that in such case said socket 4 is urged against said conical ring 3 only through the pressure of said spring [5. The axial component of the overpressure in the conical surface displaces said socket so far to the left until said piston B is held up by the bottom of said cylinder I. By the clearance thus occurring between said socket and said pivot the air escapes out of the air cylinder 2 into the free air, the oil contained in this air being caught on the bevel surfaces. By means of a setting screw 20 the clearance occurring during the air draining can be adjusted so as to ensure a satisfactory velocity of air escape and a maximum of oil being caught at the frictional surfaces.

Thanks to such arrangement resulting in automatic lubrication of the socket by that oil which otherwise would. uselessly escape into the free air together with the air from the air cylinder, a further substantial advantage is attained as against those known arrangements where the socket is to be hand-lubricated with fresh oil, this feature presenting an absolute reliability and regularity of lubrication as well as an essential saving in lubricating material.

The embodiment of the object of this invention illustrated in the accompanying drawing for the introduction of pressure air is designed for a 4 single-acting cylinder. However, by providing two or three identical sockets in side-by-side arrangement the number of air suppliers may be increased according to requirements.

It is to be understood that the embodiment described and illustrated has been chosen merely by way of example and that various modifications of constructional details may be introduced without departing from the spirit and scope of the present invention.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

1. In an arrangement for the introduction of pressure air into the rotating air cylinder of machine tools the combination comprising a distributing socket attached to the pressure air pipeline and having an inner bearing surface of conical shape adapted to support the conformably shaped pivot of the rotating air cylinder, the apex angle of the cone being of such size as to avoid self-clinching, and an auxiliary air cylinder acting through its piston and transmission means in axial direction upon said socket and pressing the same upon the conical pivot, said auxiliary air cylinder being supplied with air of the same pressure as said socket.

2. In an arrangement for the introduction of pressure air into the rotating air cylinder of machine tools according to claim 1, wherein the diameter of the auxiliary air cylinder is exceeding somewhat the value necessary to keep the distributing socket and the conical pivot in airtight relationship.

3. In an arrangement for the introduction of pressure air into the rotating air cylinder of machine tools according to claim 1, wherein the diameter of the auxiliary air cylinder is exceeding somewhat the value necessary to keep the distributing socket and the conical pivot in airtight relationship, the piston in said auxiliary air cylinder being counteracted by an adjustable spring.

EMIL REZLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

